Polyglycerol esters of mixtures mono- and bifunctional carboxylic acids are known per se:
U.S. Pat. No. 2,284,127 describes polyglycerol esters obtainable by esterification of 3 to 15 parts of a dicarboxylic acid, 20 to 40 parts of polyglycerol, and 45 to 75 parts of certain fatty acids and the use thereof as a emulsifier and wetting agent.
U.S. Pat. No. 6,242,499 describes polyglycerol partial esters comprising the esterification product of a polyglycerol mixture; saturated or unsaturated, linear or branch fatty acids having 12-22 carbon atoms; and dimer acids obtained by dimerization of fatty acids from vegetable oils having a mean functionality of from 2 to 2.4, wherein the overall degree of esterification of the polyglycerol mixture is between 30% and 75%, and wherein the degree of esterification of the polyglycerol mixture with the dimer acids is between 5% and 50%, the preparation of these polyglycerol partial esters and their use as W/O emulsifiers in cosmetic or pharmaceutical preparations and as auxiliaries for dispersing inorganic micropigments in oil dispersions.
US20050031580 describes polyglycerol partial esters of polyhydroxystearic acid and polyfunctional carboxylic acids which are obtainable by esterification of a polyglycerol mixture with polyhydroxystearic acid and dimer fatty acids, the degree of esterification of the polyglycerol mixture being between 20 and 75% and their use as W/O emulsifiers in cosmetic or pharmaceutical preparations and as auxiliaries for dispersing inorganic micropigments in oil dispersions.
Yet the fabric softening properties of the polyglycerol esters described in these documents are not usable.
Various uses for polyglycerol esters (“PGEs”) are known. See, for example, U.S. Pat. No. 4,214,038 and US 2006/0276370. PGEs are esters typically obtained by reacting polyglycerol and a fatty acid. Polyglycerols may be prepared from glycerin as described in the literature, for example, as described in U.S. Pat. No. 6,620,904. In general, oligomerization of the glycerol unit is an intermolecular reaction between two glycerin molecules to form a diglycerol. Two such oligomers can also be reacted together, or an oligomer can be reacted with an additional glycerin to form yet higher oligomers. Polyglycerols may be converted to polyglycerol esters by typical esterification techniques for example, via reaction with fatty acids, fatty acid chlorides, and the like. The fatty acids used in the esterification can be a mixture of fatty acid chain lengths such as, for example, the fatty acid mixtures derived from coconut oil or tallow. The fatty acids may be saturated or unsaturated, and may contain from about 12 to about 22 carbon atoms, or about 10 to 22 carbon atoms. The fatty acid mixtures derived from natural fats and oils such as, for example, rapeseed oil, peanut oil, lard, tallow, coconut oil, soybean oil can be converted to saturated form by hydrogenation, such processes being readily understood by one of ordinary skill in the art.
Consumer fabric treatment compositions are often formulated to provide improved fabric feel. Such compositions can be formulated, for example, as liquid softening compositions, dryer sheets, or detergent formulations. Unfortunately, depending on the type of softening active used, existing fabric softening compositions can suffer from a variety of disadvantages. For example, currently used actives can be excessively expensive, may, impart a greasy feel to textiles, and in some cases may cause treated fabric to become hydrophobic. In addition, some softening agents, such as quaternary ammonium compounds, can be difficult to formulate with, particularly when combined with anionic surfactants as flocculation/precipitation may occur. Further, there is a need for fabric softening agents that may be used in low water or compacted formulations, in contrast to currently used fabric softening agents which may be difficult to formulate as low-water compositions.
The use of polyglycerol esters in fabric softening applications has been described for example in JP3886310 which claims a fiber softening agent comprising a mixture of polyglycerol fatty acid ester and sucrose fatty acid ester.
There still is a growing demand for fabric softening substances which can be produced easily on basis of renewable sources and which give an excellent feel to the fabric.
It was an object of the invention to provide such fabric softening substances.